Loss of attachments in patients during orthodontic therapy with clear aligners: A prospective clinical study.

OBJECTIVE: This study aimed to assess the loss rate of attachments and investigate its probable influencing factors in patients during orthodontic therapy with clear aligners. MATERIALS AND METHODS: A total of 55 patients treated with clear aligners were enrolled in this prospective clinical study. The loss rate of attachments was evaluated after a 6-month follow-up since the initial bonding was finished. The attachment survival curves were gone through Kaplan-Meier estimates. The Cox regression model with shared frailty was conducted to evaluate the hazard ratios (HRs) for the following factors, including sex, age, dental malocclusion, vertical skeletal pattern, anterior overbite, operators, tooth extraction, attachment amount, arch, tooth position and attachment type. RESULTS: There were a total of 47 patients (14 males and 33 females; and mean age: 26.77 ± 8.45) in which 722 attachments were involved in the final analysis. During the 6-month follow-up, 99 attachments were lost by 40 participants. The overall loss rate was 13.7%. The loss of attachments was more common in the early months of therapy. During the first 2 months, 71 attachments were lost. The loss rate of attachments was not significantly affected by sex, age, dental malocclusion, vertical skeletal pattern, anterior overbite, operators, tooth extraction, attachment amount and attachment type (P > 0.05). The loss rate of mandibular attachments was 1.8 times that of maxillary attachments (HR = 1.8; 95% CI: 1.2-2.8; P = 0.009). The loss rate of molar attachments was 5.5 times that of incisor attachments (HR = 5.5; 95% CI: 1.6-19; P = 0.007). CONCLUSION: During the first 6 months, the overall loss rate of attachments was 13.7%. In the early months of therapy, loss of attachments was more common. The loss rate decreased as treatment time increased. Loss of attachments was significantly affected by arch and tooth position, with higher loss rates in the mandibular arch and molars. Besides, loss of attachments was not affected by sex, age, dental malocclusion, vertical skeletal pattern, anterior overbite, operators, tooth extraction, attachment amount and attachment type.

Effect of autophagy on aging-related changes in orthodontic tooth movement in rats.

BACKGROUND: The number of adult orthodontic patients is increasing, and studies have shown that autophagy is involved in regulating orthodontic tooth movement and plays an important role in aging-related changes. Therefore, we aimed to explore the role of autophagy in aging-related changes during orthodontic tooth movement by establishing a rat orthodontic tooth movement model. METHODS: Forty-five 6-week-old and sixty-five 8-month-old male Sprague-Dawley rats were selected to represent adolescents and adults and establish orthodontic tooth movement model. They were sacrificed on days 0,1,3,7 and 14. Immunohistochemistry, immunofluorescence and tartrate resistant acid phosphatase (TRAP) staining were applied to measure the expression level of osteogenesis, autophagy, aging factors and osteoclast number in periodontal membrane of left upper first molar during orthodontic tooth movement. Then, we regulated the autophagy level by injecting autophagy activator rapamycin during orthodontic tooth movement and measured these factors and tooth movement distance by micro-computed tomography. RESULTS: Aging factor levels in the periodontal membrane were higher in adult rats than in adolescent rats and the autophagy factor levels were lower. The levels of osteogenic factors were lower on the tension side in adult rats than in adolescent rats. The peak osteoclast number on the pressure side occurred later in adult rats than in adolescent rats. The injection of rapamycin increased autophagy, accelerated orthodontic tooth movement in adult rats, and reduced the levels of aging factors. The levels of osteogenic factors were higher and reached those in adolescent rats at some time points. The number of osteoclasts increased significantly in the early stage. CONCLUSIONS: Autophagy may play a substantial role in regulating aging-related changes in orthodontic tooth movement.

Comparison of pain intensity and impacts on oral health-related quality of life between orthodontic patients treated with clear aligners and fixed appliances: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to compare the pain intensity and impacts on oral health-related quality of life (OHRQoL) between orthodontic patients treated with clear aligners (CAs) and fixed appliances (FAs). METHODS: A systematic search was conducted up to December 2022 using PubMed, Web of Science, Cochrane Central Register of Controlled Trials, and Embase. Randomized controlled trials (RCTs) and prospective non-randomized controlled trials (non-RCTs) comparing pain intensity or OHRQoL between patients treated with CAs and FAs were included. The risk of bias (RoB) of individual studies was evaluated using the Cochrane RoB tool 2.0 and ROBINS-I tool for RCTs and non-RCTs, respectively. Further, meta-analyses were separately conducted for each included study using the total oral health impact profile (OHIP)-14 and visual analog scale (VAS) scores to evaluate OHRQoL and pain intensity, respectively. RESULTS: Overall, 12 studies (5 RCTs and 7 non-RCTs) were included in the study. Subgroup analyses conducted according to the total OHIP-14 scores revealed that patients treated with CAs had higher OHRQoL at 1 week, 1 month, and 6 months of the treatment. Meanwhile, subgroup analyses conducted according to the VAS scores revealed that pain levels were lower in the CA group only at 3 and 4 days of the treatment. CONCLUSIONS: Patients treated with clear aligners had higher OHRQoL than those treated with fixed appliances during orthodontic treatment. However, OHRQoL appeared to be similar between the two groups at the end of the treatment. Moreover, patients treated with clear aligners experienced lesser pain than those treated with fixed appliances on the third and fourth day after the initial treatment. The difference in pain intensity between the two treatment modalities was not noted at other time points.

Titanium Ions Promote Exogenous Calcium-Dependent Calcium Influx in Activated Jurkat T Cells: A Possible Mechanism to Explain Its Immunostimulatory Properties.

Titanium and its alloys have been widely used in dental and orthopedic implants. Owing to the biotribocorrosion behavior of implants in simulated oral environment, Ti(IV) ions could be released into surrounding tissues. Current studies have found that Ti(IV) ions could affect the biological activities of immune cells in adjacent tissues and subsequently jeopardize the long-term performance of implant prostheses. However, the potential mechanism underlying its immunomodulatory properties remains unclear. Calcium signaling has been confirmed to be involved in regulation of lymphocyte immune function. Therefore, we hypothesize that Ti(IV) ions modulated T cell function through the change of intracellular calcium concentrations. This study is aimed at exploring the role of intracellular calcium responses in the modulatory effect of Ti(IV) ions on unactivated and phytohemagglutinin-activated Jurkat T cells. Here, we confirmed that Ti(IV) ions within a certain concentration range induced CD69 expression on both unactivated and activated T cells in our study. Additionally, the combined stimulation with Ti(IV) ions and PHA increased expression of IL-1ß, TNF-α, and RANKL. Furthermore, we found that treatment with Ti(IV) induced a transitory increase in the levels of [Ca2+]i in activated Jurkat cells, dependent on the presence of exogenous calcium. Treatment with different doses of Ti(IV) for 24 h significantly increased the levels of [Ca2+]i in the activated Jurkat cells in a dose-dependent manner, but had little effect in the unactivated cells. Treatment with Ti(IV) did not significantly affect the PLCγ1 activation and inositol-1,4,5-trisphosphate (IP3) secretion in Jurkat cells. Taken together, these data indicated that Ti(IV) enhanced calcium influx during the T cell activation, independent of IP3-mediated intracellular calcium release. Our work provides insights into the mechanism involved in the regulation of lymphocyte behaviors under the effect of Ti(IV) ions, which may help to develop therapeutic strategies for dental implant failures.

Antibiotic prophylaxis for preventing dental implant failure and postoperative infection: A systematic review of randomized controlled trials.

PURPOSE: To investigate whether prophylactic antibiotics are beneficial on patients undergoing routine dental implant placement procedures and to investigate which administration regimen is the most effective. METHODS: The primary outcome was implant failure; the secondary outcome was postoperative infection. In the fixed-effects model, the Mantel-Haenszel method was used to calculate pooled relative risks (RRs) at 95% confidence intervals (CIs). To determine the outcomes, the quality of available evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). RESULTS: Prophylactic antibiotics significantly decreased the incidence of implant failure (RR, 0.29; 95% CI, 0.15-0.55; P= 0.0002; I2= 0%) but did not decrease infection. There was no statistically significant difference between single preoperative antibiotics (SPA) and preoperative and postoperative antibiotics (PPA) while treating patients with dental implant failure (RR, 1.07; 95% CI, 0.31-3.62; P= 0.92). No statistically significant difference was observed between SPA and PPA when prescribed to treat infection postoperatively (RR, 1.05; 95% CI, 0.29-3.85; P= 0.94; I2= 0%). CLINICAL SIGNIFICANCE: The administration of prophylactic antibiotics significantly reduced the failure of dental implants under ordinary conditions. Furthermore, single preoperative antibiotics and preoperative and postoperative antibiotics had similar effects on dental implant failures and infections.

Surface wear of attachments in patients during clear aligner therapy: a prospective clinical study.

BACKGROUND: This prospective clinical study aimed to quantitatively evaluate the surface wear of attachments and investigate the associated risk factors. Additionally, the wear values and regions of three types of commonly used attachments were explored. METHODS: Participants were recruited from the population of patients who received clear aligner therapy from October to December 2022. Intraoral scanning was performed on eligible participants before treatment (T0), immediately after initial bonding of attachments (T1), and at 2 months (T2), 4 months (T3), 6 months (T4), and 8 months (T5) after starting treatment. The attachment volume, average depth and regions of attachment wear were measured using superimposed digitized models. The Kruskal-Wallis test was performed to compare data between multiple groups. Multiple linear regression analyses were performed to evaluate risk factors for the volume of attachment wear. RESULTS: A total of 47 patients with 617 attachments were included. As treatment time increased, the attachment volume decreased significantly (P = 0.003). The initial attachment volume was positively related to the volume of attachment wear (ß = 0.527, P < 0.001). The volume of attachment wear was significantly greater in females than in males (ß = 0.147, P = 0.020) and in optimized attachments than in conventional attachments (ß = 0.308, P < 0.001). The wear of 3-mm rectangular attachments progressed from edges to buccal surfaces, with the deepest wear at corners of gingival edges; the wear of the optimized attachments was primarily located on surface ridges. The wear volume ratio of the optimized root control attachments was significantly greater than that of the 3-mm rectangular attachments at T3 (P = 0.011), T4 (P < 0.001), and T5 (P < 0.001). CONCLUSIONS: The volume of attachment wear increased gradually with treatment time. Sex, attachment type, and initial attachment volume were risk factors for the volume of attachment wear. The deepest wear regions of 3-mm rectangular attachments were at the corners of gingival edges, while the deepest wear regions of optimized attachments were at surface ridges. Four months after treatment, optimized root control attachments showed more relative wear than 3-mm rectangular attachments.

Preparation, characterization of basil essential oil liposomes unidirectional single-conducting water sustained-release pads and their preservation properties to Lateolabrax japonicus fillets.

The juice exudation of aquatic products oozes out during storage can influence storage quality. Herein, a novel basil essential oil liposome unidirectional water-conducting sustained-release preservation pads (BEOL/UCSP) were prepared with nylon mesh as water-conducting layer, basil essential oil liposome (BEOL) as sustained-release preservation layer, and diatomite and absorbent-cotton as water-absorbing layer. EL/UCSP, ß-CL/UCSP, and BEO/UCSP were prepared after BEOL was replaced by eugenol liposome, ß-caryophyllene liposome, and BEO. BEOL are microspheres with bilayer structure, had good storage stability, centrifugal stability, thermal stability, embedding capacity, sustained-release, and oxidation resistance, and the main components of preservatives had a synergistic effect on antibacterial properties. The pads without preservative can initially slow down quality deterioration. BEOL/UCSP can directionally absorb exudate and realize long-term sustained-release of preservative, has excellent antibacterial and antioxidant effect, and extended shelf life of Lateolabrax japonicus fillets from 6.0 days to 12.8 days. The BEOL/UCSP can provide technical theoretical support for preservation materials.

Preparation and properties of PCL coaxial electrospinning films with shell loaded with CEO and core coated LEO nanoemulsions.

During storage and transportation, the reduction of microbial contamination and management of the exudation of fluids from the fish can effectively mitigate spoilage and degradation of fish fillets. In this work, the coaxial electrospinning films loaded with natural plant preservatives, namely laurel essential oil (LEO) and clove essential oil (CEO), were prepared by the coaxial electrospinning method synergistic with nanoemulsion techniques, and the hydrophilic preservation pads were prepared. The morphology of the film fiber is clear, without beads or damage, with fiber diameters falling within the 230-260 nm range. It has a distinct core-shell structure, exceptional thermal stability, and strong antibacterial and antioxidant properties. The core-shell structure of the fiber subtly regulates the release of preservatives and significantly improves the utilization efficiency. At the same time, the synergistic use of two essential oils can reduce the amount while amplifying their effectiveness. The pads significantly slowed down the increase of key indicators of spoilage, such as total viable count (TVC), pH, thiobarbituric acid reactive substances (TBA), and total volatile base nitrogen (TVB-N), during the storage of the fish fillets. Furthermore, the pads effectively slowed down the decline in water-holding capacity, the deterioration of textural qualities, and the negative changes in the microstructure of the fish muscle. Ultimately, the pads notably delayed the spoilage of fish fillets, extending their shelf life from 5 d to 9 d. The efficient utilization of biological preservatives in this film can provide technical support for the development of food preservation materials.

Preparation and antibacterial mechanism of cinnamaldehyde/tea polyphenol/polylactic acid coaxial nanofiber films with zinc oxide sol to Shewanella putrefaciens.

In this study, the coaxial nanofiber films were prepared by coaxial electrospinning technique with cinnamaldehyde (CMA) and tea polyphenol (TP) as core material and polylactic acid (PLA) as shell material, and to obtain food packaging materials with great physicochemical and antibacterial properties, zinc oxide (ZnO) sol were added into PLA, and ZnO/CMA/TP-PLA coaxial nanofiber films were prepared. Meanwhile, the microstructure and physicochemical properties were determined, and the antibacterial properties and mechanism were investigated with Shewanella putrefaciens (S. putrefaciens) as target. The results show that the ZnO sol makes the physicochemical properties and antibacterial properties of the coaxial nanofiber films improve. Among them, the 1.0 % ZnO/CMA/TP-PLA coaxial nanofibers have smooth and continuous uniform surfaces, and their encapsulation effect on CMA/TP and antibacterial properties are the optimal. The synergistic action of CMA/TP and ZnO sol cause severe depression and folding of the cell membrane of S. putrefaciens, makes cell membrane permeability increase and of intracellular materials spillage, interference the bacteriophage protein expression, and makes macromolecular protein degraded. In this study, the introduction of oxide sols into polymeric shell materials by in-situ synthesis technique can provide theoretical support and methodological guidance for the application of electrospinning technology in the field of food packaging.

Fabrication and characterization of polylactic acid coaxial antibacterial nanofibers embedded with cinnamaldehyde/tea polyphenol with food packaging potential.

Polylactic acid (PLA) is a promising food packaging material with biocompatible, nontoxic and biodegradable. In order to reduce the deterioration of aquatic products caused by microorganisms, PLA coaxial nanofiber films with cinnamaldehyde (CMA), tea polyphenol (TP) and its composite as core materials were prepared by using coaxial electrospinning technology. Its microscopic morphology and structure were characterized separately, and its thermal stability, wettability and mechanical properties were determined. The antibacterial activity and antibacterial mechanism of nanofiber films were studied with Shewanella putrefaciens (S. putrefaciens) which is the dominant spoilage of aquatic products as the target of action. The results show that the CMA/TP (m/m = 2:5)-PLA coaxial nanofibers have small diameter, uniform distribution, smooth surface, no pores and fracture. At the same time, the film has strong hydrophobicity, good thermal stability and mechanical properties. Its antibacterial performance is better than that of single-core nanofiber films, which effectively destroys the cell membrane of S. putrefaciens, increases the permeability of cell membrane, and interferes with the synthesis and expression of its protein. The coaxial nanofiber films with CMA, TP and its composite as core material can be used as a fresh-keeping material with antibacterial properties, and has potential application value in the field of food preservation.

Preparation of WPU-based super-amphiphobic coatings functionalized by in situ modified SiOx particles and their anti-biofilm mechanism.

Fabrication of anti-wetting coatings with anti-biofouling and anti-biofilm properties has become a hot spot of attention in recent years. However, the anti-biofilm mechanism of anti-bacterial adhesion coatings with different wet resistance properties has not been explored in detail. In this work, SiOx micro-nano particles were prepared by the Stöber method and were in situ modified. The SiOx/waterborne polyurethane (WPU) coatings were prepared by the drop coating method, and the coatings with different hydrophobic and oleophobic properties were constructed by modifying the process conditions using SiOx micro-nano particles as the roughness construction factor. Taking the dominant spoilage bacteria of aquatic products, Shewanella putrefaciens as the object, the anti-bacterial adhesion properties and anti-biofilm mechanism of the SiOx/WPU coatings were investigated. The results show that, with the unmodified SiOx particles increasing from 1.2% (w/V) to 4.0% (w/V), the hydrophobicity and thermal stability of the SiOx/WPU coatings are significantly enhanced, but the oil repellency becomes worse due to the mesoporous structure. After SiOx micro-nano particles are modified with 1H,1H,2H,2H-perfluorooctyl trichlorosilane (PFOTS), the surface energy of the SiOx/WPU coatings is decreased, the liquid repellency is improved, and the surfaces are rough with the appearance of fluorocarbon compounds, but the thermal stabilities are slightly reduced. Among them, after the secondary modification of SiOx micro-nano particles, the SiOx/WPU coatings showed excellent oil repellency, lower surface energies and higher fluorocarbon content on the surface. Particularly, SiOx/WPU coatings exhibited super-amphiphobicity after adjusting the amount of concentrated ammonia added during the secondary modification process. Meanwhile, we found that for the hydrophobic SiOx/WPU coatings, the stronger the oleophobic property, the greater the anti-bacterial adhesion ability is, while the anti-bacterial adhesion ability of hydrophobic and selectively oleophobic or superhydrophobic and oleophobic SiOx/WPU coatings is poor than that of amphiphilic SiOx/WPU coatings. However, because the super-amphiphobic SiOx/WPU coatings can be in the Cassie state with the bacterial solution for a long time, it can "capture" enough air to inhibit the irreversible adhesion of the bacteria. More importantly, the coatings can also inhibit the metabolic activity, secretion of extracellular polysaccharides, and activities of ATPase and AKP of the adherent bacteria, so it has a better anti-biofilm property. The anti-biofilm coatings can be used as food packaging materials or coated on the inner surface of packaging boxes to prevent the microbial infection.

Sonochemical preparation of carbon nanosheet from carbon black.

Preparation of carbon nanosheet via ultrasound irradiation of carbon black under ambient conditions was reported for the first time. The structure of resulting carbon nanosheet was characterized by TEM, HRTEM, EDX and AFM. The experimental results showed that the carbon nanosheet is composed of ordered graphite carbon layers with a thickness of several nanometers.